1. Technical Field of the Invention
The present invention relates to an apparatus and program for supporting acoustic design of acoustic facilities.
2. Description of the Related Art
A variety of design support apparatuses or programs have been suggested for use in designing acoustic equipment in a convention facility such as a music hall or a conference center (see Patent References 1-4). These apparatuses or programs preferably display acoustic characteristics of a speaker sound receiving surface or a sound receiving surface for short, where seats or the like receiving sounds from speakers mounted in a music hall or the like are positioned, on a display device based on characteristics of a selected acoustic system before installing the acoustic equipment at the site so that the displayed acoustic characteristics can be reflected in selection of the acoustic system or in acoustic adjustment of the site.
Patent Reference 1 describes an apparatus that previously produces data of impulse responses of positions around a speaker and automatically calculates sound image localization parameters based on the produced data. In this patent reference, a template is prepared by performing FFT on the impulse responses.
Patent Reference 2 describes an acoustic system design support apparatus that automates equipment selection and design processes through a GUI.
Patent Reference 3 describes an automatic sound image localization parameter calculation apparatus that is used to obtain desired sound image localization parameters.
Patent Reference 4 describes an acoustic adjustment apparatus that automatically adjusts acoustic frequency characteristics in a short time using the difference between the characteristics of sound signals from speakers at the site and the characteristics of the sound signals received by microphones.
In addition, a design support program has been put into practical use, which calculates the number of required speakers, directions of speakers, and level balance, equalizer, and delay parameters of a sound receiving surface area using an input sectional surface shape of a music hall or the like for a planar line array rather than a 3-dimensional array in a process of preparing for acoustic equipment such as speakers.    [Patent Reference 1] Japanese Patent Application Publication No. 2002-366162    [Patent Reference 2] Japanese Patent Application Publication No. 2003-16138    [Patent Reference 3] Japanese Patent Application Publication No. 09-149500    [Patent Reference 4] Japanese Patent Application Publication No. 2005-49688
Any apparatus or program, which displays specific speaker product name candidates, has not been disclosed although apparatuses, which support speaker selection and disposition, have been suggested. Thus, to prepare a speaker, it is necessary to search a catalog for candidates that satisfy given conditions.
Any prior art document, which specifically describes determining and displaying directions in which selected speakers are to be mounted, has not been disclosed although some documents have disclosed a method or apparatus for simulating mounting of selected speakers to determine frequency characteristics of the speakers. Thus, designers themselves must repeat such simulations by trial and error to obtain optimal directions of speakers, so that they usually have trouble in designing angle conditions of speakers.
In addition, all data is not produced in frequency domain in a process of calculating a variety of acoustic parameters of sound receiving points. Thus, to align time axes of various data, it is necessary to perform a plurality of FFT or inverse FFT calculations in a process of calculating the variety of acoustic parameters, thus taking a lot of calculation time. For this reason, this method is not suitable for design that requires a lot of trial and error taking into consideration a variety of combinations of dispositions of speakers.
In Patent Reference 1, certainly, a template including Fast-Fourier-Transformed (hereafter “FFTed”) impulse responses is prepared and calculation is performed in the frequency domain. However, when time delay or attenuation due to the distances between speakers and sound receiving points are taken into consideration, responses of a plurality of speakers are summed in the time domain after being inversely FFTed to align the time axes and the data is then again FFTed. If the data is inversely FFTed to convert it to time-domain data when the time delay is great, the amount of the data is increased accordingly. This increases the calculation time of FFT, which takes a lot of calculation time, since the amount of data to be FFTed is increased.
Speakers disposed in a music hall or the like are mostly arranged into an array speaker, which combines speaker units having a plurality of orientations. Although there are such specific speaker shapes, the above patent references do not provide any specific suggestion or description about how to optimize mounting angles of the array speaker and angles between the speaker units in order to make uniform the frequency characteristics of sound pressure levels of the sound receiving surface or the distribution of the sound pressure levels.
In the related art, there is no technology for easily and automatically presenting and arranging detailed options of speakers suitable for the space shape information. The sound receiving surface is only planar as described above. In the related art, there is no technology for automatically displaying an easy-to-see three-dimensional disposition of the speaker in the space. In Patent Reference 1, CAD data is necessary for the speaker selection. It is not easy to collect the CAD data.